Persist selected manufacturer across reloads

public/app.ts

@@ -77,6 +77,7 @@ let loadRequestId = 0;
 let applicationMode = "dry-run";
 let databaseConnectionState = "unknown";
 const localDraftKey = "catalog-maker:current-product-draft:v2";
+const selectedManufacturerKey = "catalog-maker:selected-manufacturer";
 let localDraftProductKey = "";
 
 const fieldNames = [
@@ -153,6 +154,11 @@ await loadLanguages();
 languageSelect.addEventListener("change", syncLanguagePickerLabel);
 
 manufacturerSelect.addEventListener("change", () => {
+  if (manufacturerSelect.value) {
+    localStorage.setItem(selectedManufacturerKey, manufacturerSelect.value);
+  } else {
+    localStorage.removeItem(selectedManufacturerKey);
+  }
   syncManufacturerPickerLabel();
   closeManufacturerPicker();
   if (manufacturerSelect.value) {
@@ -302,15 +308,31 @@ async function loadManufacturers() {
       manufacturerSelect.append(createOption(String(manufacturer.id), manufacturer.name));
     }
     if (data.message) manufacturerSelect.append(createOption("", data.message));
+    restoreSelectedManufacturer();
     syncManufacturerPickerLabel();
     renderManufacturerOptions();
   } catch (error) {
     manufacturerSelect.append(createOption("", error.message || "Local DB is not configured."));
+    restoreSelectedManufacturer();
     syncManufacturerPickerLabel();
     renderManufacturerOptions();
   }
 }
 
+function restoreSelectedManufacturer() {
+  const savedManufacturerId = localStorage.getItem(selectedManufacturerKey);
+  if (!savedManufacturerId) return;
+
+  const savedOption = [...manufacturerSelect.options].find(
+    (option) => option.value === savedManufacturerId,
+  );
+  if (savedOption) {
+    manufacturerSelect.value = savedManufacturerId;
+  } else {
+    localStorage.removeItem(selectedManufacturerKey);
+  }
+}
+
 function toggleManufacturerPicker() {
   if (manufacturerMenu.hidden) {
     manufacturerMenu.hidden = false;